The problem w/ SBTS (and likely SEBTS) is that the modular PhD concentrations are not the biblical studies/NT/OT/theolgy that most are interested in.
==SBTS's modular PhDs are not in Biblical studies. However they do have a concentration in Apologetics & Worldview, a concentration in Christian Philosophy, and a concentration in Christian Ethics. So they do have some really good programs.
NOBTS has a strong online Biblical Studies program. They have online graduate certificates in the Biblical Languages, in Greek, in Hebrew, History, etc.
I'm pretty sure that SEBTS has PhD modules, but again it is for leadership degrees and such. Not the biblical/theological studies that modulars are just difficult.
==I checked and you are correct. They offer several PhDs in the "modified residency format". However, and on this point you are also correct, the concentrations are in leadership and missionology. Nothing I am interested in for sure.
Sadly, it is my impression that SEBTS is "behind the curve" when it comes to online programs.
I would love to jump into the PhD program at SBTS. However their residencies are during the regular Spring semester (I teach).